Randomized Trial Comparing the Flexible 19G and 25G Needles for Endoscopic Ultrasound-Guided Fine Needle Aspiration of Solid Pancreatic Mass Lesions

Abstract

Objectives: Although a large gauge needle can procure more tissue at endoscopic ultrasound-guided fine needle aspiration (EUS-FNA), its advantage over smaller needles is unclear. This study compared flexible 19G and 25G needles for EUS-FNA of solid pancreatic masses.Methods: This was a randomized trial of patients undergoing EUS-FNA of pancreatic masses using flexible 19G or 25G needle. Main outcome measure was to compare median number of passes for on-site diagnosis. Secondary measures were to compare specimen bloodiness, complications, technical failures, and histological core tissue procurement.Results: One hundred patients were randomized to EUS-FNA using flexible 19G or 25G needle. Median of 1 pass was required to achieve on-site diagnosis of 96% and 92% (P = 0.68) in 19G and 25G cohorts. There was no significant difference in technical failure (0% vs 2%, P = 0.99) or adverse events (2% vs 0%, P = 0.99) between 19G and 25G cohorts. Although histological core tissue procurement was significantly better with flexible 19G needle (88% vs 44%, P < 0.001), specimens were bloodier (severe bloodiness, 36% vs 4%; P < 0.001). Conclusions:As there is no significant difference in the performance of flexible 19G and 25G needles, needle choice for sampling pancreatic masses should be based on endoscopist preference and need for histology.Key Words: EUS-FNA, solid pancreatic mass, pancreatic cancer, pancreatic biopsy, flexible 19G needle, randomized trial (Pancreas 2015;44: 128-133) E ndoscopic ultrasound-guided fine needle aspiration (EUS-FNA) is an integral part of the diagnostic algorithm for the evaluation of solid pancreatic mass lesions. Randomized trials have compared the 25G, 22G, and 19G needles in an attempt to identify the optimal needle for tissue acquisition.1-3 Of the 3 studies that compared the 22G and 25G needles, 1-3 whereas there was no significant difference in diagnostic accuracy, there was a trend toward better performance with the 25G needle for the FNA of pancreatic head masses. These findings were confirmed in a recent meta-analysis that revealed higher sensitivity of 25G over 22G needles for the EUS-FNA of pancreatic mass lesions. 4A limitation of FNA procedures, particularly when using smaller gauge (22G or 25G) needles, is the limited ability to procure adequate histological samples. Tissue architecture and morphology are essential for accurate pathological assessment of certain lesions, such as lymphomas and gastrointestinal stromal tumors, for which histological core is preferred over a cytological aspirate. 5 Although a larger 19G needle can procure histological samples, published data are limited.6-8 In a study of 120 patients who underwent EUS-FNA using the 19G needle, the procedure was technically successful in 98.9%, and adequate histological sample was obtained in 97.5%. 6 However, patients with pancreatic head or uncinate masses were excluded in this study. A major limitation of the 19G needle has been its rigidity that makes transduodenal sampling of pancreatic masses difficult beca...